SOME BIOCHEMICAL CHANGES ON STORAGE IN POTATOES FROM PRINCE EDWARD ISLAND, AND THEIR RELATION TO THE QUALITY OF CHIPS

Abstract

Different varieties of potatoes were characterized by differences in their content of water, starch, and reducing sugar, and in susceptibility to change in response to the surrounding temperature.A critical concentration of 0.4 per cent reducing sugar was found, above which chips were dark brown, and unacceptable in flavour. Storage at 35° F. caused a rise in the concentration of reducing sugar in all varieties to between 1.5 and 4.0 per cent in 5 to 14 weeks. During storage at 50° F. the reducing sugar usually rose above 0.4 per cent in 9 to 13 weeks.Shrinkage and rot developed markedly in the Sebago, and to a less extent in the Katahdin, when the temperature was raised from 50° or 35° to 70° F., and the chips produced from them were poor in texture and flavour.A fall in the level of reducing sugar below 0.4 per cent occurred in 3 to 9 weeks during conditioning at 70° F. in the Netted Gem, Green Mountain, and Irish Cobbler varieties, and the chips from these were acceptable.The biochemical behaviour of the Netted Gem and Irish Cobbler was most conducive to the production of acceptable chips.